import random
# while True:
#     data = random.randint(0, 101)
#     print(data)
judgData = True
while judgData:
    try:
        print("Please input score")
        stuScore = float(input("Please note that the entered score cannot exceed 100 or be less than 0："))
        if stuScore <= 100:
            if stuScore < 85:
                if stuScore < 75:
                    if stuScore < 65:
                        if stuScore < 0:
                            print("YThe data you entered is incorrect ,less than 0")
                        else:
                            print("Level D")
                            judgData = False
                            break
                    else:
                        print("Level C")
                        judgData = False
                        break
                else:
                    print("Level B")
                    judgData = False
                    break
            else:
                print("Level A")
                judgData = False
                break
        else:
            print("The data you entered is incorrect ,exceeding 100")
    except Exception as e:
        print("Input information error")
    else:
        print("Successfully entered")